Surface treatment

Surface finishing treatments applied to stainless steel can take many forms. The main finishes are described below. 

Description ASTM EN 10088-2 Notes
Hot rolled 1 1E/1D A comparatively rough, dull surface produced by hot rolling to the specified thickness, followed by annealing and descaling.
Cold rolled 2D 2D A dull, cold rolled finish produced by cold rolling to the specified thickness, followed by annealing and descaling. May also be achieved by a final light pass on dull rolls.
Cold rolled 2B 2B A bright, cold rolled finish commonly produced in the same way as No. 2D finish, except that the annealed ans descaled sheet receives a final cold roll pass on polished rolls. This is a general-purpose cold rolled finish and is more readily polished than No. 1 or No. 2D
Bright annealed BA 2R BA finish produced by performing bright annealing in an inert atmosphere after cold rolling. Smoother and brighter than No. 2B.
Brushed or polished No. 4 1J/2J A general-purpose bright polished finish obtained by finishing with a 120-150 mesh abrasive, following initial grinding with coarser abrasives.
Satin polished (matt) No. 6 1K/2K A soft satin finish having lower reflectivity than brushed finish. It is produced by using a medium abrasive.
Bright polished (mirror) No. 8 1P/2P The most reflective finish commonly produced. It is obtained by polishing with successively fined abrasives then buffing with a very fine buffing compound.
Electropolished - - This surface is produced by electrolysis in an electrolytic solution. This electrochemical process improves the surface finish.

 

Guide to stainless steel finishes

The purpose of guide is to show to the architect and designer the wide range of possible surfaces at his/her disposal, to provide more detail on the processes involved and to provide basic technical advice on their application.

This guide is available in English, Czech, Dutch, Finnish, French, German, Italian, Polish, Spanish, Swedish and Turkish.
[clicking on the language will open a pdf]

Roughness measurements of stainless steel surfaces

Surface roughness is a measure of the texture of a surface. It is quantified by the vertical deviations of a real surface from its ideal form. If these deviations are great, the surface is rough, if they are small, the surface is smooth. Roughness is typically considered to be high-frequency, short-wavelength component of a measured surface. In practice, it is often necessary to know both the amplitude and frequency to ensure that a surface is fit for purpose.

Learn more here
Surface hardening of stainless steels

This brochure describes the various processes used to harden stainless steel surfaces and the properties typically obtained.

Download this brochure
Dos and donts in selecting and specifying stainless steel surface finishes

This paper, presented at the IOM workshop, So You Want to Build it in Stainless Steel, firstly outlines mill and mechanically polished (brushed) finishes to EN 10088 part 2. It goes on to discuss patterned finishes, bead-blasted finishes and electropolished finishes in a wide range of applications.
Source: British Stainless Steel Association

Download the paper here
Special finishes for stainless steel

Colorful illustrations throughout this free Designer Handbook provide a sampling of the customized, special finishes for stainless steel available in today's marketplace. Learn about etched, embossed, rolled, colored, and other special finishes, and where you can find them through the handbook's Directory of Representative Suppliers.
Source: Specialty Steel Industry of North America

Open this document
Surface finishes

Summary of the main surface finish designations and comments on where they might be appropriate.
Source: Southern Africa Stainless Steel Development Association

Open this document
Pickling and passivating stainless steel

This resource describes the surface treatments known as pickling and passivation that can be applied to stainless steel. Pickling uses nitric and hydrofluoric acids to remove a thin layer of metal from the surface.  Passivation uses nitric acid to improve the quality and thickness of the passive layer on the surface. Procedures for removing weld heat tint and rust contamination are explained.

This brochure is available in Czech, Dutch, English, German, Finnish, French, Polish, Spanish, Swedish and Turkish
[clicking on the language will open the pdf]

The mechanical finishing of decorative stainless steel surfaces

This document discusses the following points:

  • Specifying mechanically finished surfaces for stainless steel fabrications
  • Frequently used finishing methods
  • Frequently used abrasives and power tools
  • Best practice finishing
  • Case studies
  • Health, safety and environmental issues

 

This brochure is available in English, Czech, Dutch, German, Finnish, French, Italian, Polish, Spanish, Swedish and Turkish
[clicking on the language will download the pdf]

Depth, pattern and texture - the third dimension in stainless steel surfaces

When choosing a material, architects are increasingly looking not only at functional performance but also at less quantifiable characteristics, such as aesthetic effect, colour and texture, all of which have an important effect on the final result. This goes hand in hand with advances in manufacturing processes which are opening up new possibilities. This Euro Inox brochure highlights some of the possibilities and gives many examples of where three-dimensional surface structures were used and how they are created.

This brochure is available in English, Czech, Dutch, Finnish, French, German, Italian, Polish, Spanish, Swedish and Turkish
[clicking on the language will download a pdf]

Electropolishing stainless steels

Electropolishing is a chemical surface-finishing technique, by which metal is electrolytically removed, ion by ion, from the surface of a metal object. This Euro Inox brochure explains the process in more detail.

The brochure is available in English, Czech, Dutch, Finnish, French, German, Hungarian, Italian, Polish, Spanish, Swedish and Turkish
[clicking on the language will open a pdf].

Paint coating stainless steels

Stainless steels are used because of their corrosion resistance in a wide variety of service environments, usually without additional coatings. In certain circumstances, however, stainless steel components or structures may require a coated (paint) finish. Examples of this may include company colour schemes or logos, environmental blending and compatibility, and general aesthetic requirements.
Source: British Stainless Steel Association

Open this document
Pickling and passivation

Stainless steel can corrode in service if there is contamination of the surface. Both pickling and passivation are chemical treatments applied to the surface of stainless steel to remove contaminants and assist the formation of a continuous chromium-oxide, passive film. Pickling and passivation are both acid treatments and neither will remove grease or oil. If the fabrication is dirty, it may be neccesary to use a detergent or alkaline clean before pickling or passivation.
Source: Australian Stainless Steel Development Association

Open this document
Galling and galling resistance of stainless steel

Galling (cold welding) is a form of severe adhesive wear. The mechanism is briefly described. Methods for reducing galling tendency are discussed and include lubrication, nitriding and hard chromium plating.
Source: British Stainless Steel Association

Open this document
International Stainless Steel Forum (ISSF)
Avenue de Tervueren 270
1150 Brussels, Belgium
T: +32 2 702 89 00
Follow us on:
Designed by